siyuan-note/siyuan · error

Parse template failed: %s

Error message

Parse template failed: %s

What it means

Returned by RenderTemplate when the content template parses fine but fails to EXECUTE against dataModel (template.go:417). Message is Conf.Language(44). dataModel includes title/id/name/alias (and conditionally more). Execution errors come from runtime func failures, nil dereferences, or SQL func errors against the box database.

Source

Thrown at kernel/model/template.go:417

		dataModel["id"] = block.ID
		dataModel["name"] = block.Name
		dataModel["alias"] = block.Alias
	}

	goTpl := template.New("").Delims(".action{", "}")
	tplFuncMap := filesys.BuiltInTemplateFuncs()
	sql.SQLTemplateFuncs(&tplFuncMap, tree.Box)
	goTpl = goTpl.Funcs(tplFuncMap)
	tpl, err := goTpl.Funcs(tplFuncMap).Parse(gulu.Str.FromBytes(md))
	if err != nil {
		err = fmt.Errorf(Conf.Language(44), err.Error())
		return
	}

	buf := &bytes.Buffer{}
	buf.Grow(4096)
	if err = tpl.Execute(buf, dataModel); err != nil {
		err = fmt.Errorf(Conf.Language(44), err.Error())
		return
	}
	md = buf.Bytes()
	tree = parseKTree(md)
	if nil == tree {
		msg := fmt.Sprintf("parse tree [%s] failed", p)
		logging.LogError(msg)
		err = errors.New(msg)
		return
	}

	var nodesNeedAppendChild, unlinks []*ast.Node
	// 模板内部块旧 ID 到新 ID 的映射，用于成套改写模板内部的自引用
	blockIDs := map[string]string{}
	ast.Walk(tree.Root, func(n *ast.Node, entering bool) ast.WalkStatus {
		if !entering {
			return ast.WalkContinue
		}

View on GitHub (pinned to 251596fc0d)

Solutions

  1. Read the wrapped inner error (%s) — it identifies the failing function or nil dereference.
  2. For sql.* funcs, ensure the notebook (tree.Box) is fully indexed before inserting the template.
  3. Limit field access to keys present in dataModel (title, id, name, alias, plus block-derived vars).
  4. Use the 'default' template func to guard empty values.

Example fix

// before — sql func fails on unindexed box
.action{sql "SELECT ..."}

// after — index box first, or guard output
.action{sql "SELECT ..." | default "(indexing)"}
Defensive patterns

Strategy: try-catch

Try / catch

tree, dom, err := model.RenderTemplate(p, id, preview)
if err != nil {
    if strings.Contains(err.Error(), Conf.Language(44)) {
        // template execution failure; show the inner cause to the user
    }
    return handleTemplateError(err)
}

Prevention

When it happens

Trigger: A .action{} action calls a sql.* function that fails because the notebook is not indexed or the query is malformed; an action accesses a missing dataModel key; a built-in func receives wrong argument types that pass parse-time checks but fail at execution.

Common situations: Inserting a template that runs sql.* queries right after opening a notebook before indexing completes; a template referencing .action{.someKey} not in the model; a date/format func error on empty input.

Related errors

AI-assisted analysis of siyuan-note/siyuan@251596fc0d (2026-08-12). Data as JSON: /api/errors/3e3558425ba5ad63. Report an issue: GitHub.